A former Criminal Investigation (CI) Division special agent who left the IRS in 1999 over disagreements about the validity of the federal income tax, Banister was exonerated of conspiring to defraud the IRS and of helping Cencal Aviation Products proprietor Walter A. "Al" Thompson file false returns for tax years 1996-1998. Thompson was found guilty of tax evasion and failure to withhold in January 2005 and was sentenced to six years in prison.